INVESTIGATION OF NANOSTRUCTURE EFFECTS AND INTERACTIONS ON THE ELASTIC PROPERTIES OF BUCKYPAPER-POLYMER NANOCOMPOSITES

摘要

The elastic property of single-walled carbon nanotube (SWNT) buckypaper-polymer (BPP) composites depends highly on the constituent materials and their corresponding nanostructures. Although the relationships between composite nanostructure and elastic properties can be studied by traditional micromechanics models, the degree of nanostructure effect and interactions between different nanostructures are difficult to analyze because of the lack of analytical equations. In this study, a statistical design of experiment (DOE) method, the factorial design and Central Composite Design (CCD), was applied to solve this problem. Nanotube bundle length, diameter, orientation, waviness, and composite volume fraction, were considered as critical nanostructure parameters. The Mori-Tanaka method was utilized to predict the elastic properties of BPP composites. The composite axial modulus, transverse modulus, shear modulus, and Poisson ratio, were chosen as response composite properties. As a result of the CCD analysis, the bundle diameter, volume fraction and waviness were determined to be influencing parameters on the BPP composite axial tensile modulus and shear modulus. The bundle orientation is the most influencing parameter on BPP composite transverse tensile modulus. The volume fraction of the nanotube bundle was found to have a principal effect on the Poisson ratio. The optimal conditions can also be determined by using CCD analysis. Consequently, desired BPP composites can be manufactured by controlling the significant nanostructure parameters.